Alexander bryant and william j



'(No Model.)

A. BRYANT & W. J. CROW. SAFETY VALVE FOR EXPANSION PIPES.

No. 449,243. 4 Patented Mar. 31, 1891.

UNITED STATES PATENT OFFICE.

ALEXANDER BRYANT AND \VILLIAM J OROlV, OF NE\V YORK, N. Y.

SAFETY-VALVE FOR EX PANSION-PIPES.

SPECIFICATION forming part of Letters Patent No. 449,243, dated March31, 1891.. Application filed October 9, 1890. Serial No. 367,509. (Nomodel.)

To all whom it may concern:

Be it known that we, A EXANDER BRYANT and WILLIAM J. CROW, both of thecity, county, and State of New York, have invented a new and usefulImprovement in Safety- Valves forExpansion-Pipes; andwedohereby declarethat the followingis a full and exact description thereof, referencebeing had to the accompanying drawings, and to the letters of referencemarked thereon, making a part of this specification.

Our invention relates to a device for preventing a flow and waste ofwater through the boiler in the water-supply system of a dwelling-houseor other building by reason of an undue pressure in the cold-waterfeed-pipe.

In the approved systems of hot-water sup ply for a city house it iscustomary to carry an open pipe, known asan expansion-pipe, from the topof the boiler to a point above the supply-tank or highest point ofdelivery.

' This expansion-pipe operates as a safety detherein.

vice to guard the boiler against the possibility of undue pressure byreason of a generation of steam therein, provision being made for thewater which may overflow from the pipe usually by carrying the end ofthe pipe above the supply-tank. so that it may discharge Where, however,as is usually the case, the boiler is connected directly with thestreet-main, it often happens that unless pains be taken to shut offthis connection at night the increased pressure in the main which thenoccurs by reason of the lessened demand for water operates to produce aconstant flow through the boiler and out of the upper end of theexpansion-pipe, so that in a short time the hot water in the boiler willall be discharged therefrom and replaced by the cold water deliveredfrom the main.

The object of our invention is to prevent by an automatic device thisdischarge or flow of water through the boiler under this increase ofpressure; and it consistsin the combination, with the boiler, itssupply-pipe, and expansion-pipe, of a vertically-moving valve fitted tomove outwardly against a suitable seat in the end of the expansion-pipeand thereby efiectually close the pipe, and which will drop backautomatically from its seat by reason of its weight alone, so as to openthe pipe. This cut-off valve is made to close an tomatically by means ofan inverted. cup or hollow cylinder upon which the valve is carried, andwhich is fitted to play so loosely within the pipe as to permit anescape of air around it when the valve has dropped from its seat, butwhich will be carried up as a float by a column of water rising therein,and thereby lift the valve against its seat, so as to close the pipe andprevent an escape of the water therefrom, and is constructed with acentral vent-passage through it, which is closed by an auxiliary valveautomatically closed by a spring and opened when an excess of pressureoccurs in the hollow cylinder by means of a suitable float fitted insaid cylinder, all as hereinafter described and claimed.

In the accompanying drawings, Figure 1 represents in elevation ahot-water boiler with its supply and expansion pipes, the latter fittedwith our automatic cut-0d valve. Fig. 2 is an elevation upon an enlargedscale of the cut-off valve with the top deflecting-hood removed; andFig. 3, a central longitudinal section thereof in line .0: as of Fig. 2with the hood in place. I

A represents the hot-water boiler in the water-supply system of abuilding, connected in the usual manner by a circulating-pipe B with thewatcr-back in arange or other heating apparatus.

O is the eold-watensupply pipe connected directly with the main.

D is the expansion-pipe extending as is usual from the top of the boilerA to a point above the highest level of the delivery-pipes, andpreferably over the tank E.

F represents our automatic cut-off valve fitted upon the upper end ofsaid expansionpipe. This valve is constructed of a cylindrical shell orcasing F, contracted at its outer upper end, as shown in Fig. 3, so asto form an annular seat or offset g about the opening in said end, andwhich is exteriorly threaded at its opposite lower end to receive acoupling-ring ll, serving to couple it in the customary manner with aferrule K, by which to connect it with the end of the expansionpipe D.The ferrule K is of smaller diameter than the casing F, so as to formwith the latter when the two are united an internal pipe.

ofiset t. A washer L, interposed between the casing and ferrule, asshown in Fig. 3, projects inwardly to rest upon this offset.

Within the casing F is fitted a hollow cylinder N of thin metal, closedat its upperend and left free to play loosely within the casing, so asto drop and rest by its weight alone upon the washer L on the end of theferrule. The diameter of this cylinder N is such as to permit a passageof air about its periphery through the casing, its lower end beingnotched, as at M, to establish communication between the expansion-pipeD and said air passage. An open-ended tubular pin S is secured upon theouter upper end of the hollow cylinder N, and a rubber valve P is fittedupon said pin and confined by a nut T. This.

valve P is of sufficient diameter to seat itself when uplifted for thepurpose against the contracted end 9 of the casing F, so as to closethereby the opening in the end of the An auxiliary valve a is fitted toseatitself upon the upper end of this central tube S, said valve beingconnected by acentral spindle 12, extending down through the tube S,with the closed end of an inverted cup N playing freely within thecylinder N. The valve a is kept automatically closed by means of aspring W, interposed between the cup N and the top of the cylinder N,the strength of said spring being so adjusted as that it will not permitthe valve a to open under the pressure which will operate to close thevalve P, but will yield if, after said valve P is closed, the pressurebecomes so great as to endanger the boiler or pipes, and, yielding, willthereby allow the valve a to open and relieve the pressure.

A hood U is fitted over the top of the valvecasing F to deflect anywater which may be forced out through the valve F and cause it to dropback immediately into the tank E, over which the valve is located.

In the operation of our invention,when the water-pressure in the boilerA is normal, so that the level of the water in the expansionpipe D isbelow the outer end of the pipe,the cylinder N, carrying the valve P inthe valvecasiug F, secured upon the outer end of the pipe, will drop ofits own weight and rest with its lower notched edge upon the washer L,and thereby leave the aperture in the outer end of the pipe free. Withthe valve P in this position free vent is afforded to the air in theupper end of the expansion-pipe D through the notches r r in the loweredge of the cylinder N and the narrow space left between said cylinderand the inner periphery of its casing F, so as to permit the waterlevelin the pipe D to rise and fall freely, as in an open pipe. When,however, the press ure of the water-supply to the boiler has so farincreased as to cause the water to rise above the level of the valve,the water rising under the cylinder N will by reason of the air whichwill be caught and confined within said cylinder cause it to rise, andin rising will cause the valve P to close the open end of the casing F,and thus efiectually prevent an outflow of water through it, so that acirculation of the water-supply into and through the boiler and outthrough the expansionpipe cannot take place and the discharge by thismeans of the hot water in the boiler through said expansion-pipe beentirely prevented.

An undue pressure in the boiler'and expansion-pipe after the cut-offvalve P is closed from a generatiomof steam in the boiler or other causeis prevented by the operation of the central auxiliary or safety valvea.

We claim as our invention'- 1. The combination, in the water-supplysystem for a building, with the hotwater boiler, its cold-water-supplypipe and its expansion-pipe, a valve-casing fitted upon the upper end ofthe expansion-pipe and having a contracted valve-opening at the top, anda valve adapted to close said opening carried upon the upper closed endof a hollow cylinder left open at its lower end and fitted to playloosely within said casing, of a central vent-openin g through thevalve, a spring-actuated valve closing said vent, and an auxiliary floatplaced within the hollow cylinder and attached to the vent-valve to openit against the stress of its spring, substantially in the manner and forthe purpose herein set forth.

2. The combination, with the expansionpipe D, the valve-casin g F,fitted thereto,'having an opening in its outer end, and the hollowcylinder N, playing loosely in said casing, of the central tube S,secured to project from the upper closed end of the cylinder N, therubber valve P, encircling said tube and adapted to close the outer endof the valve-casing when lifted thereto, a spindle b, fitted loosely inthe tube, a valve a, fitted upon the outer end of the spindle to dropupon and close the end of the tube, an inverted cup or float N, playingloosely with the cylinder N and secured to the spindle, and aninterposed spring WV, all substantially in the manner and for thepurpose herein set forth.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing witnesses.

ALEXANDER BRYANT; WILLIAM J. CROW.

Witnesses:

A. N. J ESBERA, E. M. WATsoN.

